Dr. Walker has been responsible for the preparation of short-term forecasts and long-range projections of world economic activity and international trade that appear in analytical reports and perspective studies issued by the United Nations. In addition, he served as Secretary to the Inter-Agency Technical Working Group of the ACC Task Force on Long-term Development Objectives, the main United Nations System-wide committee coordinating technical research on economic and social issues among international agencies. Also, Dr. Walker served as a consultant to governments in the design, development and implementation of information systems and econometric models for forecasting and macroeconomic management. In this capacity, he undertook many missions to countries in Asia, Africa and Latin America as an advisor to governments. Most recently, he served as a senior economist with the Economic Outlook and Assessment Branch of the Department of Economic and Social Affairs, the research unit concerned with monitoring and forecasting current developments in the world economy.

Between 1971 and 1991, Dr. Walker was an adjunct professor of economics at Baruch College of The City University of New York, where he taught graduate classes in international economics (Spring semester) and economic development (Fall semester). From 1992 to 1995 he was adjunct professor of diplomacy and world affairs in the Occidental-at-the-United Nations program of Occidental College, Los Angeles, California, and a professor of economics at Monmouth and Old Dominion Universities. Dr. Walker has served on the boards of the Allied Social Sciences Associations, the Society for Policy Modeling and the North American Economic and Finance Association. He is a member of the New York Academy of Sciences, where he served as vice-chairman of its Section on Economics.

His present research involves the study of long-term trends in world development and the development of personal computer-based systems supporting economic research and forecasting. Dr. Walker is a member of many professional associations and is a regular speaker at the meetings of professional societies and at colleges and universities.